Actually, we are not saved by the atoning sacrifice (justification), but by the life of Jesus abiding in us(sanctification). I got this straight from the Apostle Paul when he wrote, "For if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life." Romans 5:10
The atoning sacrifice just makes us right with God (reconciled), but are we safe to save?